Abstract
Micro hot embossing, one of the important steps in the LIGA process is aimed at increasing the scale of production. The process involves: molding-in which metallic mold is pressed into the polymer, cooling-in which mold and the polymer are held together and demolding — where in the mold is separated from the polymer. In the past, these steps in a micro hot embossing process are modelled independently. As the parameters in each of these stages influence the final product quality, the simulations were performed using DEFORM 3D and by transferring the strain history from one stage to another. The final product quality thus is a function of the preceding quality in each stage. The parametric analysis shows that, at lower level of molding speed (0.01 mm/min–0.1 mm/min) and lower level of molding temperature (105°C–115°C), complete mold filling was evident. In the cooling stage, the difference between the molding and demolding temperature governs contact stresses and thermal shrinkage. At the same time, in the demolding stage, lower rate of demolding ensures lower residual stresses in the micro components formed. Experimental validation of the results shows that the predicted results agree fairly with the simulated values.
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References
Juang, Y., Lee, L., and Koelling, K., “Hot embossing in micro fabrication. Part I: Experimental,” Polymer Engineering and Sciences, Vol. 42, pp. 539–550, 2002.
Shih, Y. H., Shen, Y., Lin, Y., Lee, J., Lin, C., Lee, C., and Wu, M., “Microfluidic chip fabrication for silicon mold insert by micro hot embossing,” Proc. of IEEE Int. Conf. on Nano/Micro Engineered and Molecular Systems, Vol. 3, pp. 690–693, 2008.
Lin, C., Chen, R., and Hung, C., “The characterisation and finite element analysis of a polymer under hot embossing,” Adv. Manuf. Technol., Vol. 20, pp. 230–235, 2002.
Hirai, Y., Yoshikawa, T., Takagi, N., and Yoshida, S., “Mechanical properties of poly-methyl methacrylate (PMMA) for imprint lithography,” Journal of Photopolymer Science and Technology, Vol. 16, No. 4, pp. 615–620, 2003.
Young, W., “Analysis of the nano-imprint lithography with a viscous model,” Microelecronic Engineering, Vol. 77, pp. 405–411, 2005.
Worgull, M. and Heckele, M., “New aspects of simulation in hot embossing,” Microsystem Technologies, Vol. 10, pp. 432–437, 2004.
Guo, Y., Liu, G., Xiong, Y., and Tian, Y., “Study of the demolding process-implications for thermal stress, adhesion and friction control,” J. Micromech. Microeng., Vol. 17, pp. 9–19, 2007.
Lee, C.-S., Kang, C.-G., and Youn, S.-W., “Effect of forming conditions on linear patterning of polymer materials by hot embossing process,” Int. J. Precis. Eng. Manuf., Vol. 11, No. 1, pp. 119–127, 2010.
DEFORM, “V6.1 User’s Manual.”
Heyderman, L. J., Schift, H., David, C., Gobrecht, J., and Schweizer, T., “Flow behaviour of thin polymer films used for hot embossing lithography,” Microelectronic Engineering, Vol. 54, pp. 229–245, 2000.
Carlaw, H. and Jaeger, J., “Conduction of heat in solids,” Oxford at the Clarendon Press, Vol. 2, pp. 17–25, 1959.
Matweb, “Material Property Data.”
He, Y., Fu, J., and Chen, Z., “Research on optimisation of the hot embossing process,” J. Micromech, Microeng, Vol. 17, pp. 2420–2425, 2007.
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Jha, J.S., Joshi, S.S. Numerical simulation of micro hot embossing of polymer substrate. Int. J. Precis. Eng. Manuf. 13, 2215–2224 (2012). https://doi.org/10.1007/s12541-012-0294-x
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DOI: https://doi.org/10.1007/s12541-012-0294-x